Other Parts Discussed in Thread: UCC28951, , UCC2895, UCC28950,
Greetings,
At least one section in this datasheet seems to have been lifted directly from the datasheet for the UCC28951 and does not apply to the UCC3895.
Specifically, Section 8.2.2.10, starting on p. 34, starts out with an error, referring to "current sense signal (Pin 15)", which should say "Pin 12". It then references an Rlf and Clf which don't appear in "Figure 18. Typical Application" of the UCC2895 document, but do in Fig. 48 of the UCC28951 document. This section continues with calculations for an R1, R2, R3, and R4 that likewise appear in Fig. 48 of the UCC28951 document but not in the Fig. 18 of the UCC3895 document.
There appears to be an extra "f" in the denominator of Eq. 93.
Section 8.2.2.10.6 refers to an Rsc, which is missing from Fig. 18, unless this is a misprint for Rcs? Resistor Rel and capacitor Cc are likewise missing from Fig. 18. Meanwhile, there is no information on calculating the values for Rh, Rl, Rslc, Rclamp, etc. around Q1.
"Figure 23. Daughter Board Schematic" also appears to be misplaced.
I know these devices are fairly similar in operation, and I know that the UCC2895x devices are newer and probably recommended over the UCC3895 family, but it is still very confusing and makes me wonder what other errors exist in this design process. I'd really like to see an earlier version of the UCCx895 datasheet that has a design procedure that hasn't been corrupted by the apparent "cut-and-paste" from the UCC2895x. I'm constrained to use this part for various reasons.
Is there any way to provide a correction for these numerous errors? Would an earlier revision of the datasheet have a correct procedure? A part this complicated really needs an accurate datasheet design procedure.
Many thanks,
J. Stevens